The International Fuel Tax Agreement (IFTA) is a tax-collection compact between the 48 contiguous U.S. states and 10 Canadian provinces. It standardizes fuel-tax reporting for commercial vehicles operating across jurisdictions. If you operate a qualified commercial vehicle in two or more IFTA member states, you must register and file quarterly IFTA returns.
Who must register
Any vehicle with a gross vehicle weight (GVW or registered weight) over 26,000 lb, or any vehicle with three or more axles regardless of weight, that operates in two or more IFTA jurisdictions must be registered for IFTA. Carriers register their entire fleet under a single base-state license; owner-operators register their truck as a one-truck fleet.
How IFTA works
You buy fuel anywhere — your home state, on the road, at any truck stop. Each fuel purchase has the local jurisdiction's fuel tax baked into the pump price. Each quarter, you file a return reporting: total miles driven in each jurisdiction; total fuel purchased in each jurisdiction. IFTA calculates how much fuel tax you "owe" each state (based on miles driven there), credits the tax you actually paid (based on where you bought fuel), and either refunds or bills you the difference.
Recordkeeping
You must maintain detailed mileage and fuel records by jurisdiction for 4 years. ELDs and fuel cards (Comdata, EFS, RTS) make this nearly automatic. Modern fuel cards integrate with IFTA filing software and can pre-populate quarterly returns. Without electronic records, IFTA reconstruction from paper logs is one of the most painful clerical tasks in trucking.
When returns are due
Quarterly: April 30 (Q1), July 31 (Q2), October 31 (Q3), January 31 (Q4). Late filing typically incurs $50 to $100 in fees plus interest on any tax owed. Habitual late filing can result in IFTA license suspension, which means you cannot legally operate across state lines.
Audits
IFTA jurisdictions audit carriers periodically. Audits typically cover the past 4 years and require complete mileage and fuel documentation. Owner-operators with clean ELD records and fuel-card statements typically pass with minimal additional documentation. Read our 2290 HVUT guide for the other major federal tax requirement.